In general, as one means for discharging a suitable amount of contents, such as cosmetics, shampoo, detergent or medicine, contained in a container, a discharging pump is mounted on a container for use.
The discharging pumps according to the related art, which are mounted on a container and used to dispense a small amount of contents as described above, have been variously proposed. As shown in FIGS. 1 and 2, a general content discharging pump includes a pump body 110 in which an opening and closing ball 122, an operating piston 123 elastically supported by a spring, and a cylinder 120 for allowing the contents in a contents storing chamber 126 to be dispensed through a push button 140 by generating pressure in the contents storing chamber 126 with the operating piston 123 are installed.
An air-tight piston 124 is further installed to the operating piston 123 and the push button 140 is installed in an operating tube 130 coupled to the operating piston 123 of the cylinder 120.
According to the above-described content discharging pump of the related art, when the push button 140 is pushed, an air gap is generated between the air-tight piston 124 and the operating piston 123. In this case, a pressure is generated in the contents storing chamber 126 while the air-tight piston 124 and the operating piston 123 together move down, so that the contents are dispensed through a contents transferring passage 123a of the operating piston 123 due to the pressure.
In this case, the opening and closing ball 122 is tightly closed to a contents introducing passage 125 by the compressed spring 121 so that the contents introducing passage 125 is closed.
After the push button 140 is pushed to dispense contents as described above, when the pushed button 140 is released from the external force applied thereto, as shown in FIG. 2, the operating piston 123 and the air-tight piston 124 move up together due to the repulsive elastic force accumulated in the spring 121.
At the initial lifting stage of the operating piston 123 and the air-tight piston 124 ascending as described above, while the air-tight piston 124 is stooped ascending due to the friction with an inside of the cylinder 120, the operating piston 123 first moves up to close the air gap between the operating piston 123 and the air-tight piston 124, so that the contents transferring passage 123a is closed and the elastic force accumulated in the spring 121 is weakened.
In the state that the contents transferring passage 123a is shut off, when the operating piston 123 and the air-tight piston 124 are continuously lifted up, a vacuum pressure is generated in the contents storing chamber 125 and the opening and closing ball 122 is spaced apart from the contents introducing hole 125 due to the vacuum pressure generated in the contents storing chamber 126, so that the contents in the container are introduced into the contents storing chamber 126.
The content discharging pump according to the related art dispenses the contents while repeatedly performing the above-described operation.
However, the content discharging pump has a major drawback that, since a metallic ball and metallic spring are used as the opening and closing means for discharging contents, the metallic ball and metallic spring are corroded due to chemical reaction with the contents so that the contents are polluted. In addition, since synthetic resin and metal are used as materials of the content discharging pump, when the used content discharging pump is discarded, it is difficult to separate the synthetic resin and metallic materials from each other, so that it is difficult to perform resource recycling.
Specifically, the structure of the content discharging pump according to the related art is complex, so that the productivity is deteriorated and the product price is increased. In addition, since the discharging pump structurally has a long working stroke distance, when the discharging pump is applied to a product such as a compact having a height less than a width thereof, it is difficult to mounting the discharging pump on the product due to a small installing space.
To solve the problems described above, as shown in FIGS. 3 to 5, there has been proposed a content discharging pump having a simple structure in Korean Parent Application No. 10-2013-69816. The content discharging pump includes a deformable pressure member 260 serving as a cylinder and an opening/closing valve to have a simple structure, so that the productivity is increased and the product price is reduced. In addition, the deferrable pressure member 260 is deformed to vary the volume of a content temporary repository TR for pumping, so that the content discharging pump has a short working stroke distance, thereby allowing the pump to be easily installed in a product having a small pump installing space.
According to the content discharging pump which is coupled to a container 210 for containing contents to discharge the contents, when a push button 250 moves down, a deformable pressure member 260 is pressed, deformed, and moves downward, so that the volume of the temporary repository TR in the pump main body 220 constituting a pump upper body 222 and a pump lower body 224 is reduced to generate pressure in the temporary repository TR. Thus, a valve plate 240 closes a content outlet 226, and a valve protrusion wheel 262, which is in tight contact with a content opening/closing piece 252, is widened due to pressure, causing the contents in the temporary repository (TR) to pass through a space between the content opening/closing piece 252 and the valve protrusion wheel 262 and be discharged through an outlet 254. Thereafter, when the pressure on the push button 250 is removed, the push button 250 moves up by the restoring force of an elastic member 270 and the deferrable pressure member 260 pressed by the push button 250 is restored to the original state thereof. Thus, the pressure generated in the temporary repository TR disappears, and vacuum pressure is generated, causing the closure of the space between the valve protrusion wheel 252 of the deferrable pressure member 260 and the content opening/closing piece 252. As the central part of the valve plate 240 is raised upward due to the vacuum pressure, the boundaries of opening/closing lines 241 are widened. Accordingly, the contents inside the container 210 are transferred to the temporary repository TR through a space between the valve plate 240 and the content outlet 226, and at this moment, the contents, which have passed through the content outlet 226, are transferred into the temporary repository TR through the gaps in the widened opening/closing lines 241 of the valve plate 240. When the vacuum pressure in the temporary repository TR disappears following the transfer of the contents, the widened opening/closing lines 241 are restored to the original state thereof and closed due to the elastic force of the valve plate 240, causing the valve plate 240 to close the content outlet 226.
However, although the volume of the temporary repository TR is varied by the deformation of the deformable pressure member 260 to discharge the contents according to the pressure of the temporary repository TR and, when the pressure of the temporary repository TR is increased, the contents are discharged from the temporary repository TR while the valve protrusion wheel 262 of the deformable pressure member 260 is widened, since the entire deformable pressure member 260 is formed of soft rubber having excellent elasticity, a remaining part of the deformable pressure member 260 may be inflated before the valve protrusion wheel 262 is widened, so that it is difficult to discharge a predetermined amount of contents all the time.